It has been estimated that 80% of the protein products of the human genome are undruggable because they either lack deep hydrophobic pockets that can bind small molecules or they are inside cells where antibodies and other biological drugs cannot reach them. A goal of my group is to develop molecules that can bind these undruggable proteins and penetrate cells to create new therapeutics and molecular tools to probe biology. We have developed a unique approach to the synthesis of chemically functionalized macromolecules with programmable shapes. We have developed the synthesis of a collection of chiral, cyclic building blocks that we connect through pairs of amide bonds to create complex and pre-organized spiro-ladder oligomers, called bis- peptides, between 500 and 2,000 Daltons in weight. We have recently discovered new chemistry that allows us to incorporate a functional group on every building block. We have developed this chemistry to the point where we can create highly functionalized macromolecules that can present proteogenic and non-proteogenic groups in any three- dimensional arrangement required. In terms of diversity oriented synthesis these oligomers have very diverse three-dimensional structures by virtue of their constrained nature and rich stereochemistry. We propose to use this synthetic methodology to create functionalized bis-peptides that will mimic short ?-helices to bind helix binding proteins; mimic long ?-helices to disrupt coiled-coils; and identify protein-protein interactions in the Brookhaven Protein Data Bank that can be targeted using these oligomers. In preliminary results we have demonstrated a functionalized bis-peptide that binds Mdm2 with higher affinity than the wild-type p53 peptide and is taken up by cells. We propose to develop functionalized bis-peptides that simultaneously bind Mdm2 and Mdmx and others that bind c-Myc and study their ability to enter and arrest growth in liver cancer cells.